Duplicate Line Remover
Remove repeated lines from lists and text instantly. Preserve the original order or sort the result, ignore case, trim whitespace, remove blank lines, and choose whether to keep the first or last occurrence.
Last updated September 6, 2026
6
Input lines
4
Unique lines
2
Duplicates removed
33%
Reduction
How to Remove Duplicate Lines
Clean a repeated list in a few steps:
- Paste your text or list, or open a .txt file.
- Choose whether duplicate matching should be case-sensitive.
- Decide whether to ignore surrounding whitespace or remove blank lines.
- Choose whether to keep the first or last occurrence and whether the final list should stay in its original order or be sorted.
- Copy or download the cleaned result.
Everything is processed directly in your browser.
Duplicate Matching Options
Each option changes how lines are compared or how the result is arranged:
- Case-sensitive matching treats Apple and apple as different values. Turn it off when capitalization should not create separate entries.
- Ignore surrounding whitespace treats “ item ” and “item” as the same value for comparison without necessarily changing the retained output text.
- Remove blank lines deletes empty or whitespace-only lines from the final result.
- Keep first / Keep last controls which occurrence survives when the same line appears multiple times.
- Preserve order / Sort preserves the original sequence by default, or alphabetically sorts the unique output when requested.
Duplicate Line Removal Example
Input:
apple banana Apple apple cherry banana
With case-sensitive matching ON:
apple banana Apple cherry
With case-sensitive matching OFF:
apple banana cherry
In both examples, “Keep first occurrence” is selected, so the first surviving spelling and position are retained.
What Can You Deduplicate?
A duplicate line remover is useful for cleaning many one-item-per-line lists, including:
- Email addresses
- URLs and domains
- Keyword lists
- Product SKUs
- Tags and categories
- Log entries
- IDs and reference numbers
- Exported spreadsheet columns
- Repeated code imports or configuration lines
For structured CSV rows containing quoted delimiters or multiline fields, use a dedicated CSV tool rather than treating each physical line as a complete record.
Frequently asked questions
Which copy of a duplicate line is kept?
By default, the first occurrence is kept. You can switch the tool to keep the last occurrence instead.
Does the tool preserve the original order?
Yes, by default. Sorting is optional and only happens if you select A–Z or Z–A.
What does case-insensitive matching do?
It treats lines such as Apple and apple as the same value for duplicate detection.
Can I ignore extra spaces around lines?
Yes. Enable “Ignore surrounding whitespace when comparing” so “ apple ” and “apple” count as duplicates.
Can I remove empty lines too?
Yes. Enable “Remove blank lines” to delete empty or whitespace-only rows.
Can I see how many duplicates were removed?
Yes. The results show input lines, unique lines, duplicate lines removed, and the reduction percentage.
Is my list uploaded?
No. Deduplication runs locally in your browser.
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